Freshly prepared pizza style pies are frequently packaged in cardboard containers or cartons, referred to as “pizza boxes”, to maintain freshness and temperature. Pizza boxes are often formed by folding a single sheet of paperboard or cardboard to form a square base panel, four wall panels standing upright therefrom to a relatively uniform height and a lid hinged to the upper edge of one of the wall panels. Usually the lid includes flaps extending from the three edges of a cover panel other than the edge with the hinge connection such that the lid may be pivoted about its hinged connection to the remaining wall panel to close a rectilinear space within the container and pivoted open to gain access to the contents of the pizza box. The flaps about the lid are usually arranged to fit inside the three walls when the pizza box is in its closed disposition.
Pizza boxes often have ventilation holes, the cardboard sheet from which one is formed nearly always being scored and slit at appropriate locations so that when it is folded up to form the pizza box, the parts lock together to prevent “unfolding” of the pizza box. Typically, the side walls of the pizza box are formed as “roll-over” walls formed by having an outer wall panel extending from the edge of a base panel, and an inner wall panel extending from a wall top edge of the outer wall panel remote from the base panel, the relative widths of the outer and inner wall panels being such that the distal edge of the inner wall panel engages with the base panel at or near to a fold line along which the outer wall panel may be folded with respect to the base panel when the inner wall panel is folded with respect to the outer wall panel along the wall top edge until it is substantially alongside the outer wall panel. In this specification, the term “roll-over” walls refers to this and similar arrangements.
Additionally, even though pizza boxes are formed from single cardboard “blanks”, the panels forming the boxes being joined along fold or score lines which are constituted by a weakening of the material, the term “edge” is used in this specification to refer to the join line between two adjoining panels even though the panel may be contiguous with one another.
Many pizza restaurants promote their wares not only on the pizza boxes themselves, but also with pamphlets, brochures, flyers and the like, sometimes by letterbox drops, and sometimes with the product sold from their restaurants or delivered to purchasers. Pizza boxes also represent one of the major overheads for pizza restaurants, and it could be advantageous if the cost of the boxes could be offset.